This invention relates to tube bending tools and more particularly to a manually operable tube bender especially suited for effecting bends in excess of 90 degrees.
Manually operated tools for bending tubing are quite old and well known in the art. For example, such tools are widely used by electricians for forming bends in an electrical conduit. Examples of commercial tube benders sold by Stride Tool Inc. and its predecessors are described and claimed in U.S. Pat. Nos. 4,379,360, 4,220,642, 4,289,872, 4,229,873, 4,343,496, 4,379,340, and 4,424,660 (xe2x80x9cthe Stride patentsxe2x80x9d). The tools described in the Stride patents are capable of bending tubes up to 180 degrees. While these tools have enjoyed long standing commercial success, the tools are somewhat awkward for use in effecting bends in excess of 90 degrees because the handles, which are manipulated by an operator to effect the bend, cross over when a tube is being bent beyond 90 degrees. When the handles cross over, manipulation of the tool becomes somewhat awkward and difficult. Moreover, an operator in bringing his hands toward one another through the first 90 degrees after the cross over, an operator""s force application is reversed and one is pulling one""s hands apart or pressing with crossed arms.
Another tool that has been available commercially for a period of time requires disconnection of one of the handles after a 90 degree bend has been completed by unscrewing the handle from the tool element to which it is connected. The handle is then reconnected by threading it into other threaded recess to effect bending from 90 degrees up to 180 degrees.
Accordingly it would be desirable to produce a manually operated tube bender which is capable of effecting bends up to 180 degrees without handle cross over or the need to disconnect and reconnect one of the handles after 90 degrees of bending has been accomplished.
In one embodiment according to the present invention, a tube bender comprises a mandrel, a forming member connected to the mandrel for coaction with the mandrel to effectuate at least 180 degree bending of a tube wherein the forming member has at least two bending positions defined thereon, a handle pivotally connected to the forming member, a release member movable relative to the handle wherein the release member is associated with the handle; and engagement means for securing the release member in a locked position relative to the forming member when the handle is selectively moved to any of one the at least two bending positions thereby preventing relative movement between the handle and the forming member. The release member enables an operator to move the release member to an unlocked position to permit such operator to move the handle relative to the forming member between the at least two bending positions.
Preferably, the release member is a sleeve disposed about the handle. The tube bender may further comprise a biasing element, such as a spring, disposed between the sleeve and the handle to resiliently bias the sleeve in a direction towards the forming member. Alternatively, the tube may further comprise a biasing element, such as a spring, disposed between the sleeve and the handle to resiliently bias the sleeve in a direction away from the forming member.
Also, the tube bender may further comprise urging means for permitting an operator to move the release member in an axial direction relative to the handle with at least one finger of the operator""s hand that holds the handle. The urging means may comprise an actuation lever having a finger-receiving portion and a coupling portion wherein the finger-receiving portion extends from the release member to enable such operator to actuate the finger-receiving portion of said lever with a finger of the same hand holding the handle without having to reposition such operator""s hand. The coupling portion of the lever is operably connected to the release member wherein the activation of the finger-receiving portion of the lever causes the release member to move axially to the unlocked position.
The engagement may comprise a first structure disposed on the forming member defining a first of the at least two bending positions, a second structure disposed on the forming member defining a second of the at least two bending positions, and a complimentary structure disposed on the release member. The complimentary structure engages the first structure when the handle is moved to the first bending position thereby securing the release member in the locked position. The complimentary structure engages the second structure when the handle is moved to the second bending position thereby securing the release member in the locked position. The first structure may define a first notch and the complimentary structure may define a tab that engages the first notch when the handle is moved to the first bending position. The second structure may define a second notch and the complimentary structure may define a tab that engages the second notch when the handle is moved to the second bending position.
In another embodiment according to the present invention, a tube bender comprises a mandrel, a forming member connected to the mandrel for coaction with the mandrel to effectuate at least 180 degree bending of a tube, the forming member having at least two bending positions defined thereon, a following member pivotally connected to the forming member defining a pivot point, a handle movable axially relative to the following member wherein the handle is associated with the following member to thereby permit the handle to rotate about the pivot point relative to the forming member, and engagement means for securing the handle in a locked position relative to the forming member when the handle is selectively moved to any of one the at least two bending positions thereby preventing relative movement between the handle and the forming member. The handle enables an operator to move the handle axially to an unlocked position to permit such operator to move the handle relative to the forming member between the at least two bending positions.
Preferably, the following member is a shaft disposed within a cavity provided in the handle. The tube bender may further comprise a biasing element, such as a spring, disposed between the shaft and the handle to resiliently bias the shaft in a direction towards the forming member. Alternatively, the tube may further comprise a biasing element, such as a spring, disposed between the shaft and the handle to resiliently bias the shaft in a direction away from the forming member.
To move, the handle into the unlocked position, the operator may pull the handle in an axial direction away from the following member or the operator may push the handle in an axial direction towards the following member.
In another embodiment according to the present invention, a tube bender comprises a mandrel, a forming member connected to the mandrel for coaction with the mandrel to effectuate at least 180 degree bending of a tube, the forming member having at least two bending positions defined thereon, a handle pivotally connected to the forming member, a release member pivotally connected to the handle, engagement means for securing the release member in a locked position relative to the forming member when the handle is selectively moved to any of one the at least two bending positions thereby preventing relative movement between the handle and the forming member, and an actuation lever operably connected to the release member to enable an operator to actuate the actuation lever thereby moving the release member to an unlocked position to permit such operator to move the handle relative to the forming member between the at least two bending positions.
To move the release member into the unlocked position, the operator may push the actuation lever in an axial direction towards the following member or the operator may pull the actuation lever in an axial direction away from the following member.
In another embodiment according to the present invention, a tube bender comprises a mandrel, a forming member connected to the mandrel for coaction with the mandrel to effectuate at least 180 degree bending of a tube wherein the forming member has a socket in communication with at least two channels defining at least two bending positions in a first plane, a handle having a ball portion disposed in the socket and a shaft portion disposed in one of the at least two channels for securing the handle in a locked position relative to the forming member when the handle is selectively moved to any of one the at least two bending positions thereby preventing relative movement between the handle and the forming member. The handle may be adapted to enable an operator to move the handle into a geometric plane different than the first plane to an unlocked position to permit an operator to move the handle relative to the forming member between the at least two bending positions.